F. Abel, E. Herder, P. Kärger, D. Olmedilla, and W. Siberski. Creating New Learning Experiences on a Global Scale, Second
European Conference on Technology Enhanced Learning, EC-TEL
2007, Crete, Greece, September 17-20, 2007, Proceedings, volume 4753 of Lecture Notes in Computer Science, page 143-157. Springer, (2007)